JButton fire with a space or enter key or mouse click

I am trying to get a simple JFrame with a single button to fire an event when any of these events happen:

• Enter key pressed and JButton has focus
• Spacebar is pressed and JButton has focus
• Click the JButton button.

It seems that Enter and space come "free" along with the default mouse click using addActionListener on JButton; The problem is that I read that the key bindings depend on the Look and Feel used.

I tried to get universal behavior through LaF by adding Enter and a space in the JButton action map and even added a random key ("m") to make sure the ActionMap was doing the job (that was), but now the mouse click is lost. The only way I can get all the keys and a mouse click is to use both an action map and addActionListener.

Is there a way to get these keyboard and mouse bindings to work consistently in all LaFs, without trying to detect all the possible LaFs that might appear? Can I register one action listener that will fire for both events and the mouse?

My favorite solution would be to add a mouse click to the JButton action map and determine which key or mouse click occurred inside the action.

, , , -; , . , , . !

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;

import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.InputMap;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.UIManager;

public class Example extends JFrame {

// ============================
private class BtnListener extends AbstractAction {
    private static final long serialVersionUID = 1L;

    public void actionPerformed(ActionEvent ae) {
        System.out.println("\nclick button listener triggered");
        System.out.println(ae.getSource().getClass().toString());
    }
} // class BtnListener

private static final int NO_MODIFIER = 0;
private static final boolean ON_KEY_PRESS = false;
private static final KeyStroke ENTER_PRESSED = KeyStroke.getKeyStroke(
        KeyEvent.VK_ENTER, NO_MODIFIER, ON_KEY_PRESS);
private static final KeyStroke M_PRESSED = KeyStroke.getKeyStroke(
        KeyEvent.VK_M, NO_MODIFIER, ON_KEY_PRESS);
private static final KeyStroke SPACEBAR_PRESSED = KeyStroke.getKeyStroke(
        KeyEvent.VK_SPACE, NO_MODIFIER, ON_KEY_PRESS);
private JButton btnButton;
private final AbstractAction btnListener = new BtnListener();
private JPanel buttonPanel;
private JFrame frmMain;

public static void main(String[] args) {
    Example ex = new Example();
    ex.displayFrame();
}

Action btnActionListener = new AbstractAction() {
    private static final long serialVersionUID = 1L;

    public void actionPerformed(ActionEvent e) {
        System.out.println("\nkey button action triggerred");
        System.out.println(e.getSource().getClass().toString());
        if (e.getSource() instanceof JButton) {
            System.out.println("button");
        } else {
            System.out.println("Something else");
        }
    }
};

public Example() {
    initialize();
}

public void displayFrame() {
    try {
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    } catch (Throwable e) {
        e.printStackTrace();
    }
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                frmMain.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

private void initialize() {

    frmMain = new JFrame();
    btnButton = new JButton("Abutton");

    // Comment this out, you lose the mouse click
    btnButton.addActionListener(btnListener);

    // Comment out ActionMaps, but keep addActionListner (above), and
            // only lose M_PRESSED
    InputMap buttonFocusedMap = btnButton
            .getInputMap(JComponent.WHEN_FOCUSED);

    buttonFocusedMap.put(ENTER_PRESSED, "blah");
    btnButton.getActionMap().put("blah", btnActionListener);

    buttonFocusedMap.put(SPACEBAR_PRESSED, "blort");
    btnButton.getActionMap().put("blort", btnActionListener);

    buttonFocusedMap.put(M_PRESSED, "gaaak");
    btnButton.getActionMap().put("gaaak", btnActionListener);

    // Is there a way to add a mouse click to the ActionMap?

    buttonPanel = new JPanel();
    buttonPanel.add(btnButton);

    frmMain.getContentPane().add(buttonPanel);
    frmMain.setBounds(100, 100, 500, 432);
    frmMain.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

}